1. Field of the Invention
The present invention relates to a mobile measurement system of three-dimensional structure to measure a three-dimensional structure of the measuring object such as plant community and the others with non-destruction, non-contact and over a broad area.
2. Description of Related Art
A result of the measurement of the three-dimensional structure of a plant community is used as one of the characteristic of the dynamism of a wood (a kind of plant life) or a forest (a kind of plant community) to evaluate it ecologically. Therefore, the measurement of the three-dimensional structure of a plant community with non-destruction and non-contact is important and, for example, the inventor of this invention suggests the technique of the structure measurement with a laser plane range-finding method (T. Tanaka, J. Yamaguchi and Y. Takeda: “Measurement of forest canopy structure with a laser plane range-finding method—development of a measurement system and applications to real forests”, Agricultural and Forest Meteorology 91, pp 149–160, 1998).
However, the measurement of the three-dimensional structure of a plant community by using a laser plane range-finding method must be executed by following steps:
1) Locate a slit floodlight to illuminates slit light to the plant community and a digital still camera to take a picture of the plant community which is illuminated by the slit light from the direction of across that of the slit light at a predetermined position.
2) Take a plurality of pictures of the plant community according to the various directions of the illumination of the slit light by change the directions of the illumination of the floodlight.
3) Obtain the three dimensional structure of the plant community by combining the position and the direction of the floodlight and the camera at the taking each pictures and each pictures of the plant community by the camera to obtain the cross-sectional structure of the plant community. Thereby, there is a problem that the characteristic of the structure of the forest is hard to be fully comprehended because the measurement is only carried out within a narrow area as the range of 20 m–50 m from the floodlight and the camera which are located at the predetermined position, respectively.
To solve the problem, there was attempted to a moving measurement by locating the equipments such as rails, a crane and an aerial railway and executing the measurement with obtaining the various locations of the flood and the camera. However, this measurement has further problems that there is costly and troublesome to locate the equipments, and the equipments has a risk that it will makes a damage to the environment of the plant community.
Furthermore, there was also attempted to another moving measurement with obtaining the locations of the various locations of the flood and the camera by global positioning system (GPS), but this measurement in turn has a problem that the measurement by GPS is not able to executed in the area such as in the forest, or the other area such as under the forest canopy because the electric wave from the GPS satellite is hard to reach such area.